Weeds cause tremendous global economic losses by reducing crop yields and lowering crop quality. In the United States alone, agronomic crops must compete with hundreds of weed species, including barnyardgrass, broadleaf weeds and sedges. Moreover, the application of some herbicides to control such undesirable plant species has caused some crop damage due to inadvertent exposure to those herbicides.
Therefore, research efforts continue to discover and develop more effective herbicidal agents for the selective control of weeds. Such agents are desirably effective even while growing in the presence of crops so that inadvertent uneven application will cause less crop damage, if not eliminating such damage altogether.
Sulfamoyl urea derivatives are described in U.S. Pat. Nos. 4,666,508 and 4,741,762. The sulfamoyl urea derivatives disclosed therein demonstrate herbicidal activity but do not provide a showing of selective weed control in the presence of crops.
U.S. Pat. No. 5,009,699 discloses a crop-selective, herbicidal sulfamoyl urea derivative. However, that compound is outside the scope of the present invention.
It is an object of the present invention to provide compounds which are highly effective for controlling undesirable plant species.
It is also an object of the present invention to provide a method for controlling undesirable plant species.
It is a further object of this invention to provide a method for the selective control of undesirable plant species growing in the presence of crops.
These and other objects of the present invention will become more apparent from the detailed description thereof set forth below.